1. Field of the Invention
This invention relates to the art of casting formed concrete products. More particularly, this invention relates to an apparatus and method for making a plurality of formed products at one time and providing a convenient means for removing the final products from their molds.
2. Description of the Prior Art
Concrete products such as bumper curbs, railroad ties, fence posts, and patio blocks are usually produced in molds that are large and cumbersome to handle. The molded products are usually made either one at a time or in a multicavity mold which requires at least two workers and additional heavy equipment for lifting and inverting the molds to remove the cured product. No single apparatus is available that is capable of forming multiple concrete products while also providing both a vibrating means and means for removing the final formed products.
For example, Gaudelli et al., in U.S. Pat. No. 4,228,985 discloses a mold bed having a number of mold cavities wherein the molded parts are readily removable by suspending the entire mold bed and formed products on a pedestal and turning the bed upside-down to eject the molded parts by gravity. Several disadvantages are inherent in this type of apparatus. First, the mold bed when filled with concrete is very heavy and it takes at least two men or a forklift to place it on the pedestals prior to inversion. Furthermore, should one desire to vibrate the wet cement mixture after it is poured into the molds, one would have to attach a separate vibrator system. Also, the Gaudelli et al. mold bed lacks versatility in that it can only be used for making elongated mold products such as concrete spacers used in parking lots.
Bratchell, U.S. Pat. No. 4,038,355 teaches combining a multi-cavity mold with a tilt device for lifting one side of the mold to pivot it about a longitudinal axis, lowering the mold, and inverting it in order to discharge the concrete ties formed therein. There are several disadvantages encountered with the production method disclosed in Bratchell. First, effective use of the tilt mold frame requires additional heavy machinery, for example mounting a separate vibrator on to the hopper which is filled with wet cement. Secondly, a forklift truck must be used to support the filled mold prior to the lifting and tilting steps. Also, in order to lift the mold frame containing the formed concrete ties, it is necessary to provide a hoist system which is attached to a crane.
As is evident from the above discussion of the prior art, what is needed is an apparatus capable of making a plurality of formed concrete products having all the necessary equipment for making the products incorporated into a single apparatus that can be operated by just one person with minimum manual effort.